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  Food Micro & Innovation  
  Ensuring the safety of animal feed: a Blueprint for the Future  
  By S. Notermans and G.C.Mead  
  S. Notermmans, Foundation Food Micro & Innovation, Obrechtlaan 17, 3723KA Bilthoven, The Netherlands  
  G.C. Mead, International Food Safety Consultant, 17 Harbutts, Bathampton, Bath BA2 6TA, United Kingdom  
 
  On Friday, 12 December 2003, the Foundation Food Micro and Innovation held an international symposium in Edegem, Belgium. The main purpose of this meeting was to introduce the idea of a conceptual model, based on scientific principles, for ensuring the safety of animal feed. Such a model would also take account of animal health and welfare requirements and, in turn, would ensure that foods of animal origin were safe for human consumption, while satisfying public perceptions of safety demands. Thus, the new model would pave the way for introducing Good Manufacturing Practices and Hazard Analysis Critical Control Point principles, and future legislation. Another aim of the Symposium was to identify those aspects of feed production in which improvements were needed so that, ultimately, feed could be produced to the highest standards in all respects.  
  Why better control is needed  
  In the last few years, society has been confronted by several feed-related crises. Specific incidents have included those due to contamination of feed with prions, that can cause BSE (1998), PCBs and dioxins (1999), the hormone medroxy progesterone acetate (2002) and nitrofurans (2003). In some cases, these incidents have involved fraudulent activities by either companies or individuals, leading to contamination of raw materials and ultimately finished feed. However, the consequences are generally the same, involving not only economic losses and sometimes harm to animals receiving the feed, but also a decrease in consumer confidence in the feed industry. The problems have also attracted political attention. For example, the Dutch Parliament has investigated in 2003 the situation regarding feed safety in the Dutch feed industry and has now adopted a General Feed Law who has to be implemented from October 2004 onwards. The European Commission is challenging the feed industry to take whatever steps are necessary to improve this undesirable situation. If the industry is unable to improve its practices significantly, it is likely that the European Commission will take the initiative. In that case, safety requirements can be expected to become more stringent and may even exceed those currently applicable to human food. The main reason is that no risk will be taken in the future that foods of animal origin could be tainted by contaminants occurring in animal feed. However, experience to date suggests that, in itself, more regulation will not be sufficient to convince environmental pressure groups and a sceptical public that controls are adequate.  
  The above developments have raised the profile of feed production and, not surprisingly, the recent problems have had a very strong negative impact. To improve the situation, the industry must be prepared to develop better controls that will also satisfy demands on animal health and welfare and environmental concerns relating to livestock.  
  In setting up the symposium, the organisers have consulted many stakeholders. These comprised directors and various other staff of feed manufacturing companies and companies producing foods of animal origin, legislative authorities, bodies representing the suppliers and traders of feed ingredients, representatives of farming organisations and feed and food commodity boards, and scientists and other academics involved in feed and food safety issues. This consultation resulted in a programme in which keynote speakers introduced the main topics and indicated any gaps in our scientific knowledge that needed to be filled.  
  The key topics  
  In his introduction, Dr Piet Vanthemsche, Chief Executive Officer of the Belgian food safety agency, drew attention to the many contaminants in feed that were not yet regulated. He made a plea for an acceptable alternative to the zero-tolerance approach to some unwanted substances, since the levels detectable by analytical methods were still diminishing. He also recognised the present lack of knowledge concerning the transfer of hazardous substances from feed to food products of animal origin.  
  Dr Brian Cooke, an animal feed consultant in the UK, focussed on animal health and welfare issues and environmental consequences of feed usage. While feed was seen as an important vehicle for veterinary medicines and zootechnical products, there were also perceived hazards to human health. In addition, Dr Cooke highlighted the technical deficiencies in feed production that resulted in a carry-over of ingredients and cross-contamination of different batches of feed. He also stressed the important role of nutritionists in formulating balanced diets to protect animal heath and welfare, while reducing the environmental impact of animal production.  
  Dr Servé Notermans a principal scientist of the TNO Nutrition and Food Research Institute in The Netherlands, presented a general outline of requirements for the production of safe animal feed, based on the setting of 'feed safety objectives' (FSOs). The system made use of principles governing animal health and welfare, and covered environmental and legal aspects, as well as the safety criteria set for human food. Establishment of FSOs involved the use of risk analysis, as described by the Codex Alimentarius Commission, despite gaps in our knowledge of hazard characterisation and factors such as the transfer of hazardous agents from animal feed to human food. With regard to the latter aspect, special attention needed to be given to mycotoxins and zoonotic agents of infectious disease. In relation to animal health and welfare, Dr Notermans called for a generic approach to feed control.  
  Dr Catherine Cadiou of the French Socofag Company paid particular attention to the decontamination of raw materials used in feed manufacture. 'Decontamination' was defined as the elimination of a hazardous contaminant (physical, chemical or microbiological), or its reduction to an acceptable level. Although prevention of contamination was recognised as the best option, there were other, attractive alternatives that provided remedial action. However, important gaps in present knowledge were recognised, especially in relation to decontamination technology (mechanical cleaning and sorting, absorption by an inert material, hydro-thermal treatment), as well as in sampling and analytical procedures. The zero-tolerance approach was also singled out for attention.  
  Winfried Leeman of the TNO Nutrition and Food Research dealt with the transmission of toxic substances from feed to food, which involved various kinetic processes, including absorption, distribution, metabolism and excretion by the animal. To set maximum residue levels for toxic contaminants in feed, data on their transmission was considered essential. TNO had developed a database in which the quantitative transfer of chemicals was recorded and expressed in terms of 'transfer factors'. Although the current database contained more than 2500 individual transfer factors, it was not yet comprehensive and needed to include both probabilistic and 'maximum-transfer' factors.  
  Prof Lynn Frewer, Research Chair in Food Safety and Consumer Behaviour at Wageningen University, The Netherlands, focussed on the importance of risk communication and discussed two case studies, one on BSE, which began in 1996, and the other on dioxins, beginning in 1999. Both showed the need for industry and regulators to improve communication with the public. This would lead to wider public involvement in risk management processes and take account of public opinion in formulating policy. A key issue relates to the effective communication of uncertainty. Regulations would need to accommodate societal values as well as estimates of risk. To operate such an approach, procedures would need to be standardised, so that outputs were comparable.  
  Prof Leo den Hartog, affiliated to both Wageningen University and Nutreco, The Netherlands, brought the meeting to a close with a talk entitled 'Turning theory into practice'. He pointed out that the feed market was a global one, involving some 587 million tons of feed in 2001. While poultry feed was the largest sector (35 %), fish feed was showing the strongest growth. Emerging issues included the need for traceability throughout the entire supply chain. Here, important factors were response time (customers expect a rapid response), the negative effects of mycotoxins, such as a decreased growth-rate in pigs due to deoxynivalenol-contamination of feed, and the need to check suppliers and their products. Scientific input is needed for technical issues, such as' transfer factors', validation of analytical methods and the setting of more realistic criteria. This also applied to better, more transparent communication and consumer education.  
  Present needs for research and improved control measures  
  Various gaps in present knowledge were identified during the talks and from the discussion forum at the end of the meeting. These indicate a number of needs, which include the following:  
  •Raw materials  
   Selection of raw materials and maintenance of their quality are key aspects of feed production. Any decontamination process should aim to minimise the carry-over of toxins or microbial contaminants to the finished feed. In each case, attention should be given to the likely effects of decontamination on human health risks, including possible hazards from chemical products derived from toxin conversion.  
  •Transfer factors  
   Metabolism of toxic substances in the animal itself could reduce some human health hazards, but the metabolic processes involved are poorly understood, as is the transfer of toxic substances from animal feed to human foods of animal origin. The use of 'transfer factors' can help in assessing possible risks to human health, both for substances in the current database and those that are not yet included, provided that the relevant properties are known. Although the present database gives 'transfer factors' for a broad range of contaminants and a number of livestock species, it is far from complete. Also, risk assessment is needed to establish acceptable levels of transfer for substances not in the database that have to be assessed generically.  
  •Predictive modelling  
   This technique has been used successfully in the food industry in controlling chemical and biological hazards, but has yet to be applied to feed production. Possible applications include the evaluation of decontamination treatments and assessment of product storage-life.  
  •Feed in relation to animal health and welfare  
   Feed is important in both respects and is also a common vehicle for medication. It must meet certain compositional criteria to avoid any deficiencies in essential nutrients, while providing optimum digestibility. In both cases, the criteria need to be better defined.  
  •Risk analysis  
   This process has not been properly applied to feed production, especially in relation to risk assessment and communication. Risk communication is an important element in risk analysis and needs to be developed for feed. In particular, it is vital to gain the trust of consumers through the determination of risk for vulnerable groups in society and by making available all necessary information.  
  •Acceptable levels of contamination  
   The increasing sensitivity of methods for detecting hazardous chemical contaminants in feed makes the 'zero-tolerance' approach unworkable and apparently unnecessary. Instead, criteria for taking appropriate action should be established.  
  •Application of the HACCP concept  
   The starting point should be the setting of official FSOs. These would be, in each case, an expression of the maximum frequency and / or concentration of a physical, chemical or biological hazard in feed at the point of consumption that provides an appropriate level of health protection for the animal. The FSOs should correspond to those for foods of animal origin that are intended for human consumption. Determination of FSOs should be based on risk analysis and these must be internationally acceptable. FSOs would be achieved by applying performance criteria to production processes that meet both nutritional and safety requirements. Such processes must be controlled by appropriate codes of practice and implementation of the HACCP system. Feed producers would need to establish suitable controls for the purchase of raw materials and for conditions of feed production, storage and distribution. These controls should be subject to independent auditing. Advantages of the HACCP system include monitoring of CCPs, establishment of corrective action and use of verification procedures. With this approach, pro-active control of feed production is guaranteed.